BACKGROUND OF THE DISCLOSURE
[0001] The present disclosure relates generally to elastic composites and alternatively,
to absorbent cores. More particularly, the present disclosure relates to elastic absorbent
assemblies. Such an elastic absorbent assembly is well suited as an elastic absorbent
core for a disposable absorbent article, preferably disposed centrally on the chassis
thereof. The present disclosure also relates to a system and method of making the
elastic absorbent assembly or elastic core assembly, or a disposable absorbent article
incorporating the elastic core assembly. To illustrate various aspects of the disclosure,
exemplary and preferred embodiments are described herein in the context of disposable
absorbent garments.
[0002] Disposable absorbent garments contemplated by the disclosure include disposable diapers,
disposable pull-on garments, training pants, and the like. These garments are worn
about the lower torso or waist of the user so as to receive and contain urine and
other bodily waste. Disposable pull-on garments include training pants, pull-on diapers,
disposable underwear, and adult incontinence garments. As for training pants, these
garments are used by young children to facilitate a child's transition from using
diapers to wearing regular underpants (
i.e., during toilet training). Training pants and other disposable pull-on pants have
closed sides such that the user or caregiver raises the garment about the user's legs
to wear the garment and slips the garment downward about the user's legs to take it
off.
[0003] The principal elements of a typical disposable absorbent garment generally include
a liquid permeable inner layer (or topsheet), a liquid impermeable outer layer (or
backsheet), and an absorbent core sandwiched between the inner and outer layers. Elastic
members may be incorporated into different parts of the garment. For example, elastic
members may be positioned longitudinally along a diaper, generally outboard of the
absorbent core to effect a seal around the buttocks or legs of the user. In addition,
several elastic members (e.g., in the form of elongated elastic threads or strands)
may be positioned laterally throughout the waist regions (including the side waist
regions) of a disposable absorbent garment. The resulting elastication allows the
garment to stretch when it is put on and when it is worn. The elastication allows
the garment to accommodate variations in waist size and leg size of the user, while
fitting snugly about the waist and legs.
[0004] Most absorbent articles used today as baby diapers have a general configuration similar
to that of the absorbent article 10 depicted in FIGS. 1A and 1B. The conventional
absorbent article 10 is shown in a laid out flat position in FIG. 1A, and in cross
sectional view in FIG. 1B. It is common, among those skilled in the art, to describe
the garment and its construction, especially the relative positions of its components,
with the garment in the laid out flat position. This absorbent article 10 includes
an outer-side fluid impermeable backsheet 101, a bodyside, fluid permeable nonwoven
coverstock or topsheet 102, and an absorbent construction 110 positioned between the
backsheet 101 and topsheet 102. An absorbent core 103 provides the primary component
of the absorbent construction 110 and is designed and positioned to receive and retain
bodily fluids. The absorbent construction 110 may also include at least one fluid
management, fluid distribution and/or surge layer 104.
[0005] As shown in FIG. 1A, the backsheet 101 and topsheet 102 together form or define a
chassis or central body 105 of the absorbent article 10. The central body 105 may
be described as having a first longitudinal end edge 112a, a second longitudinal end
edge 112b, and a longitudinal centerline YY that extends through the central body
111, bisecting both the first and second end edges 112a, 112b. Left and side margins
106a, 106b extend from one end edge 112a to the other end edge 112b. Each end edge
112a, 112b partly defines waist regions 113a, 113b of the central body 105 which are
generally characterized as having a lateral width significantly greater than a lateral
width of a central region or crotch region 114 of the central body 105. The waist
regions 113a, 113b are designed to allow the absorbent article 10 to be placed about
the waist of the user. In this respect, the first and second waist regions 113a, 113b
may be described as front and rear waist regions 113a, 113b, respectively. The conventional
absorbent article 10 further includes a fastening means 104 attached to each side
of the rear waist region 113a. The fastening means 104 are extendible and thereby,
fastenable to a corresponding side of the front waist region 113b. The fastening means
104 helps to retain the article 10 around and on the body of the user. The absorbent
article 10 also includes a means for elasticizing 107 the article 10 to maintain closure
and sealing around the user's legs. The elasticizing means 1057 (
e.g., leg cuffs and/or leg cutters) are necessarily positioned outboard of and along longitudinal
side margins 106 of the absorbent construction 110. Referring to FIG. 1A, the conventional
absorbent core 110 is centrally positioned in and about a crotch region 114 of the
absorbent article 10.
[0006] Most diaper cores are made from mixtures of fibers and superabsorbent particles,
specifically cellulose based fibers derived from wood pulp and superabsorbent particles
(SAP) derived from polyacrylic acid derivatives. See e.g.
U.S. Patent No. 6,540,853. SAP-nonwoven absorbent composites of the type disclosed in this patent reference
are available to the diaper manufacturing process in roll form and allow much greater
freedom for the design of absorbent cores. Nevertheless, because fluff pulp-superabsorbent
cores are generally provided as a continuous stream or web of absorbent material,
the simpler and most cost efficient processes require the absorbent core to be maintained
in a generally rectangular shape.
[0007] These cores are typically formed into rectangular shapes that are designed for incorporation
into an absorbent article. The core shape, particularly its width, is maintained at
dimensions that accommodate placement within a diaper corresponding with the crotch
area of the user. Moreover, it is preferred in many applications for the absorbent
core to take on a nearly hourglass shape. Such diaper cores are known in the art as
providing a narrower crotch region that presents a better fit and comfort for the
user. The hourglass shape also provides wider regions at the longitudinal ends of
the core, which enhances the absorbency and leakage control capability of the diaper
at those regions above the central crotch region.
[0008] As known in the art, the preferred diaper assembly process is a substantially linear
and efficient machine directed process that produces a high volume of packaged products.
Because of the nature of the consumer product as a disposable, high frequency of use
item and the abundance of competing products and alternative products (
e.
g., re-usable cloth diapers), it is imperative to maintain the low cost of the final
product. Accordingly, it is also imperative to control the complexity of the manufacturing
process and to minimize steps and material waste. This presents a technical challenge
to one attempting to create alternative shapes and functionalities in the conventional
disposable absorbent article. For example, although an hourglass shaped diaper core
is generally desirable or, in some applications, a core having distinct areas of absorbency,
additional cutting or forming steps or increased material cost may make the alternative
design less effective.
[0009] FIGURE 1C illustrates another prior art disposable absorbent article 10'. The absorbent
article 10' employs a design in which an absorbent core 110' is reduced in width in
the crotch region 114', but is wider at the front and rear waist regions 113a', 113b'.
The result is an absorbent core 110' having a more hourglass shape. To achieve this
desired hourglass shaped core, a rectangular absorbent core section is cut from a
continuous web of absorbent material and shaped further, particularly in forming the
narrow central region.
[0010] In any event, absorbent core configurations achieving further functionalities and/or
improved fit and comfort for the user or wearer are desirable. Caution must be exercised,
however, to minimize material cost and manufacturing complexity.
[0011] United States patent application publications
US2005/0131373A1 and
US/2005/0139311A1 provide background information on elastic composites (and the manufacture of such
composites) of the type relevant to the present disclosure. Accordingly, some portions
of the publications have been included herein to facilitate description of the disclosure.
These publications and documents are also directed to an elastic composite having
cross-directional elasticity, as well as a system and method of making the same. More
specifically, these prior publications describe elastic composites in which an elastic
construction imparts generally lateral elasticity to the composite in a direction
that corresponds to the cross-machine direction. Such an elastic composite provides
certain advantages and benefits for the disposable absorbent article, and also, the
system and method of making the elastic composite and the disposable absorbent article.
For example, the provision of such an elastic composite or a sub-process of making
an improved elastic composite affords flexibility, efficiency, and productivity in
the system and process. These advantages and benefits translate further to cost efficiency
and cost savings.
SUMMARY OF THE DISCLOSURE
[0012] The present disclosure relates generally to elastic composites and alternatively,
absorbent cores. The invention is defined in the claims. Specifically disclosed herein
are elastic absorbent assemblies and a system and method of making the elastic absorbent
assembly. Such an elastic absorbent assembly is well suited as an elastic absorbent
core for a disposable absorbent article, disposed centrally on the chassis thereof.
Thus, the elastic absorbent assembly may be referred to as an elastic or elasticated
core composite or assembly, and in the context of a disposable absorbent garment.
Whether referred to as an elastic absorbent assembly, elastic core composite, or elastic
core assembly, it is contemplated that the elasticized absorbent product or products
disclosed has applications beyond disposable absorbent garments.
[0013] Also disclosed are a system and a method of making the elastic absorbent assembly
or elastic core assembly, and further, a disposable absorbent article incorporating
the elastic core assembly.
[0014] In one aspect, an elastic absorbent assembly includes a top layer, a bottom layer,
and an elastic construction therebetween. The elastic absorbent assembly further includes
absorbent material supported between the two layers. Preferably, the elastic construction
is composed of spaced apart elastic strands sandwiched between the two material sheet-like
layers, and preferably adhered to one or both layers (to elasticize the absorbent
assembly). Furthermore, the nonwoven layers are preferably bonded, at least partially,
along a direction generally transverse to the elastic strands, thereby forming or
urging a plurality of encapsulating spaces between the layers and in which absorbent
material is supported. A line along which one or more bond sites are situated to bond
the layers together may be disposed along the sides of the encapsulating spaces to
further define the encapsulating space. A plurality of such bond lines may be disposed
transverse to the plurality of elastics to define a plurality of said encapsulating
spaces.
[0015] In one embodiment, an elastic absorbent assembly for incorporation into a disposable
absorbent garment is presented. The elastic absorbent assembly comprises an a base
layer, a top layer, and an elastic construction disposed in between, or sandwiched
by, the top and base layers. The elastic construction is provided by a plurality of
spaced apart elastic elements forming, with the base and top layers, a plurality of
encapsulating spaces or preferably elongated capsules, wherein absorbent material
is disposed. Preferably, the top and base layers are nonwoven and the absorbent material
includes, but is not limited to, superabsorbent polymer particles.
[0016] Moreover, the elastic construction preferably comprises a plurality of spaced apart
elastic elements in the form of strands, filaments, and the like. The elastic elements
are preferably secured to one or both of the top and base layers at spaced apart or
intermittent bond sites or points, thereby forming the encapsulating spaces. In such
a core construction or assembly, the elastic elements are directed transversely to
the direction of the elongated encapsulating capsules, which direction of the elastic
elements being the lateral and cross-machine direction and the direction of the capsules
being the longitudinal and machine direction. Between the bond sites mutually securing
the top and base layers and the elastics, the two layers may be unbonded or bonded.
Thus, the two layers may be bonded continuously at laterally spaced, preferably continuous
bond lines that also hits or crosses most, if not all, of the spaced apart elastic
elements at the aforementioned bond sites or bond points.
[0017] In another embodiment, the elastic absorbent assembly further comprises another top
or cover layer, preferably nonwoven, extending over the first top layer. The cover
layer may be substantially unsecured to the top layer and may form additional void
spaces therebetween (upper void spaces). In some embodiments, additional absorbent
material may be provided in portions of the upper void spaces.
[0018] In some embodiment, the superabsorbent polymer particles are located in at least
some of the plurality of capsules.
[0019] In certain embodiments, the sizes or shapes of the capsules are non-uniform and may
vary from capsule to capsule or from one region of the core assembly to another region.
[0020] In still other embodiments, the elastic absorbent assembly further comprises an acquisition
layer.
[0021] In specific embodiments, the elastic absorbent assembly further comprises a distribution
layer between an acquisition layer and the primary elastic core assembly comprising
the capsules.
[0022] In some embodiments, the constituents of the capsules are non-uniform and may vary
from capsule to capsule or from one region of the core assembly to another region.
[0023] In some embodiments, the top and base layers are bonded between the capsules so as
to segregate one capsule from adjacent capsules.
[0024] In some embodiments, the top and base layers are un-bonded between the capsules or
in certain segments between bond sites of the elastic elements, such that one capsule
is disposed in fluid communication with or open to adjacent capsules.
[0025] In some embodiments, the elastic construction is comprised of two sets of spaced
apart elastic elements that are disposed transverse to one another, such that elastics
of the first set cross elastics of the second set.
[0026] In some embodiments, the elastic construction is comprised of two sets of spaced
apart elastic elements that are disposed transversely to one another, thereby forming
pockets or cells bounded by elastics and the top and base layers.
[0027] In some embodiments, the elastic construction is comprised of two sets of spaced
apart elastic elements that are disposed transversely to one another, thereby forming
pockets or cells bounded by four segments of elastics and the top and base layers
bonded to the four segments of elastics. In further embodiments, the pockets provide
an all-around cell or pocket enclosure in which absorbent material is deposited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028]
FIGS. 1A and 1C are plan views of a conventional disposable absorbent garment in the
unfolded configuration;
FIG. 1B is an longitudinal cross sectional view of the disposable absorbent garment
in FIG. 1A;
FIG. 2 is a perspective view of a disposable absorbent garment in the form of a diaper,
in the open, unfastened configuration, according to the present disclosure;
FIG. 2A is a simplified plan view of the disposable absorbent garment in FIG. 2, in
an open, flat configuration;
FIG. 2B is an end cross sectional view of the disposable absorbent garment in FIG.
2A;
FIG. 2C is a simplified plan view of an alternate disposable absorbent garment, according
to the present disclosure, in an open, flat configuration;
FIG. 3 is a plan view of an elastic composite shown in an extended, stretched condition,
according to the prior art;
FIG. 4 is a perspective view of the elastic composite with a cut-out to show an elasticized
region, according to the prior art;
FIG. 5 is RESERVED;
FIG. 6 is a schematic of prior art system and process for making an elastic composite;
FIG. 7 is a top view of an elastic element applicator assembly for use with the system
of FIG. 6;
FIG. 8 is a side view of the assembly of FIG. 7;
FIG. 9 is a simplified process illustration of making an elastic composite, according
to the prior art;
FIG. 10 is a simplified process illustration of making the elastic composite, according
to the prior art
FIG. 11 is a simplified illustration of a prior art cross-directional elastic composite;
FIG. 12 is a simplified illustration of a cross-directional elastic composite in the
prior art;
FIG. 13A is a simplified process illustration of a system and method of making the
elastic composite in FIG. 12;
FIGS. 13B-C are simplified illustrations of a system of making the elastic composite
in FIG. 12;
FIG. 13D is a simplified illustration of an alternative system of making elastic composites;
FIG. 14 are comparative illustrations of the elastic composite in FIG. 12 in a relaxed
state and in an extended state;
FIG. 15 is a simplified illustration of yet another elastic composite;
FIG. 16 is a simplified system and process illustration of making the elastic composite
in FIG. 15;
FIG. 17 is a simplified illustration of an extender subsystem suitable for use with
the system and process illustrated in FIG. 16;
FIG. 18 is a simplified illustration of yet another elastic composite in the form
of an elastic laminate;
FIG. 19 is a simplified illustration of yet another elastic composite in the form
of an elastic laminate having pre-folded sections;
FIG. 20A is a simplified illustration, in plan view, of an exemplary elastic core
assembly, according to the present disclosure;
FIG. 20B is a simplified illustration, in cross-sectional end view, of the exemplary
elastic core assembly in FIG. 20A, according to the present disclosure;
FIGS. 21A-21C are simplified illustrations, in cross sectional end view, of alternate
elastic core assemblies, according to the present disclosure;
FIGS. 22A-20C are simplified illustrations of alternative elastic core assemblies,
according to the present disclosure;
FIG. 23 is a simplified illustration, in plan view, of yet another exemplary elastic
core assembly, according to the present disclosure;
FIG. 24A is a simplified schematic of an exemplary system and method of making an
elastic core assembly, according to the present disclosure;
FIG. 24B is a simplified illustration and isometric of a system for making an elastic
core assembly, according to the present disclosure;
FIG. 25 is a simplified illustration, to accompany the schematic of FIG 24, of a suitable
sub-process of conforming a substrate for input into the process according to FIG.
24;
FIGS. 26A- 26B are simplified illustrations, in perspective view, of a pre-conformed
substrate for use in the making of an elastic core assembly, according to the present
disclosure;
FIGS. 27A-27C are simplified illustrations of a set of rollers for corrugating a substrate
for use in the elastic core assembly according to the present disclosure;
FIG. 28 is an isometric of a suitable sub-process and sub-system, to accompany the
schematic of FIG. 24, for making an elastic composite for input to the process according
to FIG. 24;
FIGS. 29A and 29B are simplified schematics of alternate systems and methods of making
an elastic core assembly, according to the present disclosure;
FIG. 30 are simplified illustrations of providing substrates of different configuration
for receipt of absorbent material, according to the present disclosure;
FIGS. 31A-31B are cross sectional views depicting the stretched and un-stretched configurations
of exemplary elastic core assemblies, according to the present disclosure;
FIGS. 32A-32B are cross sectional views depicting alternate configurations of exemplary
elastic core assemblies, according to the present disclosure;
FIG. 33 is an illustration for showing the selective placement SAP-filled capsules
relative to a baby waist contours;
FIGS. 34A-34D are simplified illustrations, in perspective view, of alternate elastic
core assemblies, according to the present disclosure;
FIG. 35 are simplified illustrations, in cross-sectional view, of alternate elastic
core assemblies with additional absorbent material-loading capacity, according to
the present disclosure;
FIG. 36 are simplified illustrations, in cross-sectional view, of alternate elastic
core assemblies incorporating additional absorbent material-loading capacity and a
dual top cover layer, according to the present disclosure;
FIGS. 37A-37D are simplified illustrations, in perspective view, of alternate elastic
core assemblies, according to the present disclosure;
FIG. 38 is a process diagram of making a multi-directionally elastic core assembly,
according to the present disclosure; and
FIG. 39 is a simplified illustration and isometric of a system and a method for making
a multi-directionally elastic core assembly according to the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE DISCLOSURE
[0029] Generally, the present disclosure relates to an elastic composite, and to a system
and method for making the elastic composite. More particularly, the disclosure is
directed to an elastic composite having cross-machine or cross-directional elastic
or stretch properties. Such an elastic composite is sometimes referred to herein as
an elastic composite having cross-directional elasticity and further, as a cross-directional
elastic composite.
[0030] As described previously, various aspects of the present disclosure are particularly
suited to or for a disposable absorbent garment, such as baby diapers and training
pants. To illustrate the disclosure and preferred embodiments of the disclosure, much
of the following Detailed Description will be provided in the context of such disposable
absorbent garments. It is contemplated that various aspects of the inventive composite,
garment, system, and process may be applicable to other material structures and processes.
This Detailed Description and exemplary embodiment should not, therefore, be construed
as limiting the disclosure to the structures, configurations, methods, and processes
described herein.
[0031] As described previously, the conventional absorbent article 10 is shown in a laid
out flat position in FIG. 1A, and in cross sectional view in FIG. 1B. An absorbent
core 103 provides the primary component of the absorbent construction 110 and is designed
and positioned to receive and retain bodily fluids. For purposes of the present description,
the backsheet 101 may be further formed from two or more backsheet material, and include
elastics incorporated therewith, to define an elasticized chassis or central body
105 of the absorbent article 10
[0032] FIGS. 2 and 2A-2C are simplified illustrations of one embodiment of a disposable
absorbent garment in the form of a diaper, according to the present disclosure. FIG.
2 shows the diaper 200 in an open configuration, incorporating an elastic core assembly
201 according to descriptions further provided below. FIGS. 2A-2C provides additional
views of such a typical diaper 201, except modified in design, to incorporate the
elastic core assembly. In respect to FIGS. 1A-1C, like reference numerals are used
in FIGS. 2A-2C to indicate like elements. To illustrate beneficial characteristics
of the elastic core assembly 201, when incorporated with elasticized chassis, the
diaper 200 is further provided with two backsheet materials 106a that sandwich a series
of elastic strands 120, as known in the art. Notably, elastics 120 are placed beneath
the core assembly 201, as well as beyond.
[0033] FIGS. 3, 4, and 6-8 are provided for background and to illustrate elasticized composite
and processes for making the elastic composite related to the present disclosure.
Some Figures, and accompanying description, are provided to illustrate the prior art
and for the purpose of highlighting the contributions to the prior art provided by
the present disclosure. The same Figures also illustrate use of the elastic composite,
system, or method of the disclosure, and/or a product derived from the inventive elastic
composite. FIGS. 3 and 4 show prior art elastic composites. FIG. 6 illustrates a prior
art system, system components, and a process of making the elastic composite having
a single elasticized region as previously described and disclosed in the prior art.
See
U.S. Patent Application Nos. 10/733,649 and
11/021,424. These Figures and accompanying descriptions of the prior art are provided to facilitate
description of the present inventive elastic composite and highlight the differences
and improvements provided by the present inventive system and method.
[0034] FIG. 3 depicts a typical elastic composite band 210, now generally known in the art,
but which may also be derived from the elastic composite of the present disclosure.
The elastic composite band 210 is one particularly suited for use as a side panel
or fastening tab of a disposable absorbent garment. FIG. 5 provides a perspective
view and partial cutout of the elastic composite band 210. The elastic composite band
210 may be characterized by an imaginary centerline LL. The centerline LL preferably
corresponds with the machine direction of the elastic composite band 210 during manufacture.
The elastic band 210 also has side or longitudinally extending side edges 210a and
210b and laterally extending end edges 210c and 210d. In FIG. 3, the elastic composite
band 210 is shown in the stretched state as, for example, when a garment incorporating
the elastic composite band 210 is worn. In this state, the elastic composite band
210 stretches, in the lateral or cross-machine direction (denoted by arrows XX).
[0035] As used herein, the term "machine" direction refers to the direction at which the
component, or more particularly, the material web from which the elastic composite
is derived (
e.g., cut from) is driven in an assembly line during manufacturing. The term "cross-
machine direction" or "cross-directional," on the other hand, refers to the direction
that is transverse to the machine direction. With reference to the elastic composite
210 of FIG. 3, the cross machine direction is the direction XX extending laterally
relative to the longitudinal line LL. As sometimes described herein, such an elastic
composite may be described as a "cross-directional" elastic composite or as exhibiting
cross-sectional elastic properties.
[0036] The elastic composite band 210 has a central region 214 in which an elastic construction
214 is situated. Extending laterally from this central elastic or elasticized region
214 are regions 216 and 218, which are substantially non-elasticized ("dead zones").
As shown in FIG. 3, the regions 216, 218 occupy the expanse between the central elastic
region 214 and the side edges 210a, 210b.
[0037] FIG. 6 is provided to illustrate a known system, and system components, and process
of making or manufacturing an elastic composite, as previously practiced and described
in more detail in
U.S. Patent Applications 10/733,649 and
11/021,424. In the prior art process illustrated therein, two elastic composite web outputs
1031 are produced from four separate non-woven web inputs 1003a, 1003b, 1003c, and
1003d. Referring first to FIG. 6, a system 1001 includes four separate non-woven web
inputs 1003a-1003d, which provide a web or roll of non-woven material for the elastic
composite. The system further includes an output assembly or reel 1005 that receives
two elastic composite webs 1031 from the rest of the process. These two separate elastic
webs may be later fixed together after manufacturing to produce the kind of composite
having two elasticized regions.
[0038] Central to the system 1001 is a conveyor assembly 1009 for receiving, manipulating,
and conveying each of the non-woven web inputs. The conveyor assembly 1009 is positioned
and operatively associated with an elastic element applicator such as a spinning head
assembly 1007. The assembly 1007 applies elastic fibers or strands upon, onto, and/or
integrally with the non-woven web inputs. The spinning head assembly 1007 further
includes a spinhead 1017, preferably in the form of a spinning bracket, or cylinder
1017 and the like. The spin cylinder 1017 is configured to hold an "end section" of
the continuous strand WW of elastic and move it about a generally vertical plane XX
in a reciprocal or repetitive pattern (relative to the conveyor assembly 1009). This
plane XX is defined by the area within the spinning perimeter of the cylinder 1017
and which is traced by the outer most bracket or eye 1017b securing the strand of
elastic WW to the spin cylinder 1017. The paths of the spinhead 1017 and the section
of elastic strand retained thereby are provided on the plane XX.
[0039] As shown in the schematic of FIG. 6, non-woven inputs 603a and 603b are fed, utilizing
a series of rollers, into the conveyor assembly 1009. Before the two non-woven webs
are fed into the conveyor assembly 1009, the webs are directed through the folding
guides or plates 1039. The folding guides 1039 serve to effectively reduce the overall
width of the non-woven web by folding the lateral or side edges along a pre-determined,
longitudinally-extending side fold line YY. The first folding guide 1039a initiates
the first 90° turn while the second folding guide 1039b initiates a second 90° turn.
The roller 1039 disposed in between the guide 1039a, 1039b facilitates the folding
process. The two folding guides 1039 and roller 1369 may be referred together as a
folding guide assembly.
[0040] The conveyor assembly 1009 is set up so as to guide these two non-woven webs 1003a
and 1003b through the center of the assembly 1009 towards and eventually inside the
elastic spin cylinder 1007 (into the spinning path). Once inside the spin cylinder
1017 the conveyor assembly 1009 delivers the non-woven webs to each outside, upper
and lower faces (outward faces) of the conveyor assembly 1009. At this point, the
direction of travel of the non-woven webs is reversed and the webs are directed outward
from the spin cylinder 1007. As the non-woven webs exit the spin cylinder 1017, an
elastic strand WW is wrapped around the entire conveyor assembly 1009, and as it contacts
the upper and lower face of the web platforms it comes into contact with the non-woven
web. As shown in several of the Figures, the elastic strand WW is applied crosswise
or laterally on the web, and transverse to the direction of the moving web. The friction
between the tensioned elastic strand and the non-woven webs on the upper and lower
faces of the conveyor assembly draws the "wrapped" elastic strand out of the spin
cylinder 1017 and towards contact with two further non-woven webs 1003c and 1003d.
[0041] The non-woven webs 1003c and 1003d are operatively positioned upstream of an adhesive
applicator 1013. Utilizing a system of rollers in conjunction therewith, the non-woven
inputs 1003c, 1003d and adhesive applicators 1013 apply a web of pre-glued non-woven
material onto the conveyor assembly 1009 and onto the elastic strand "wrapped" around
the non-woven webs 1003a and 1003b.
[0042] Furthermore, the system 1001 employs a standard elastic input source, e.g., a bobbin
of elastic yarn, that feeds elastic strands or fibers WW onto a tensioning/speed controlling
unit 1037 and then to the spin cylinder or the spinning head 1017, so as to apply
the strands WW onto the conveyor assembly 1009 and the non-woven material webs conveyed
therethrough. Elastic is taken off the bobbin, box or positive drive system and fed
through a tension and speed controlling motor towards the spin cylinder 1017. The
elastic WW is delivered through a hollow shaft in the motor controlling the spin cylinder
1017. The elastic WW then passes into the spin cylinder 1017 and is guided by rollers,
eyes or any other suitable mechanism around the inside face of the spin cylinder 1017.
[0043] As shown in FIG. 6, the spinning head assembly 1007 is positioned about and in the
vicinity of one end of the conveyor assembly 1009. In operation, the spinning head
1017 spins about the vertical plane XX which intersects the ends of the web moving
platforms 1412 so as to deliver the elastic strands WW around and about both web moving
platforms 1412. In operation, the first and second non-woven move along the outside
or exposed surfaces or sides of the web moving platforms 1412 and receives the elastic
strands WW delivered by the spinning head 1017. By way of its movement away from the
spinning head 1017, the moving web draws the continuous elastic strand WW from the
spinning head 1017.
[0044] FIG. 6 and the above accompanying description illustrates a method of making an elastic
composite that is different from and precedes the present disclosure. Most of the
steps, sub-processes, components and subsystems associated with the method may be
employed, however, in the systems and methods of the present disclosure. In fact,
applicable detail descriptions of system components and operation may be borrowed
from this portion of the specification to illustrate the inventive systems and methods.
Differences between the previously disclosed systems and the systems to be described,
in respect to the present disclosure, represent, or arise from, improvements provided
by the present disclosure. Such differences are discussed below in more detail.
[0045] The descriptions shifts now to an alternative and, for some applications, improved
but still prior art system and process for producing an elastic composite having a
plurality of mutually spaced-apart elastic elements, and, more preferably, such an
elastic composite having cross-directional elasticity. FIGS. 11 through 17 are provided
to help illustrate such an elastic composite with cross directional elasticity, and
systems and method of making the elastic composite. In further design variations,
the elastic composite has a pair of non-elasticized regions or dead zones and a central
elastic region positioned therebetween. Of particular concern is an alternate method
of making a continuous web of elastic composite having cross-directional elastic properties,
with marked improvements in efficiency, productivity, flexibility, and/or economy.
As discussed herein, such an elastic composite may lend itself to post-processing
and integration of the elastic composite into various components of a disposable absorbent
article.
[0046] As discussed previously, the term "elastic composite" is used to refer to a multi-component
material construction that includes elastic elements. In some products, the elastic
components include one or more nonwoven layers and elastic elements that impart elasticity
on the nonwoven layer(s). In further designs, such an elastic composite is in a form
suitable for direct integration as a component in a disposable absorbent article.
Such an elastic composite may be fed directly into a system and main process for making
a disposable absorbent article. In other product designs, the elastic composite is
in a form that is well suited for further processing before integration as a component
in a disposable absorbent article. For example, the elastic composite provided herein
may be a novel construction that captures the target cross-directional elastic properties
of a plurality of elastic elements and provided in a form that facilitates further
processing. In one further example, the elastic composite is a laminate construction
that captures a desired multi-layered elastic construction and in a form that can
yield a plurality of individual cross-directional elastic composites in ready form.
In other examples, the novel laminate construction is further processed to yield individual
cross directional elastic composites having a multilayered central elastic region
and, in a further example, a pair of non-elastic regions or dead zones.
[0047] With the methods of manufacturing discussed earlier, particularly, elastic composites
featured a central elastic region having a width that is depended on, and thereby,
limited by, certain manufacturing parameters. Specifically, the lateral or cross-directional
width of the elastic region in the stretched state is fixed by the dimensions of certain
manufacturing components. For example, the diameter of the spin head (and also of
the vertical plane XX; imposes a length limitation on the elastic elements in the
central elastic region. The spin head encircles the conveyor assembly and thus, the
width of the nonwoven web that is supported on the conveyor assembly must be less
than the diameter of the spin head. Such a limitation on the length of the elastic
element also dictates the minimum width of the nonwoven sheet onto which the elastic
element is applied. Similarly, the width of the conveyor that conveys the nonwoven
to the spin head, and about which the elastic is wrapped, dictates the practical width
of the nonwoven sheet and thus, the length of the elastic elements. Furthermore, the
diameter of the spin head is limited by the practical speed of the manufacturing process.
In FIGS. 13-19, systems and methods are provided that readily allow for a cross directional
elastic composite having a relatively wider elastic region. In yet another example,
a system and method are provided for varying the width of the elastic region.
[0048] FIG. 11 is provided to illustrate a type of elastic composite 1110 relevant to the
present disclosure. The conventional elastic composite 1110 has a central elastic
region 1114 in which an elastic construction 1114 is situated and non-elastic regions
(dead zones) 1105, 1106, each aside the central elastic region 1114. The elastic composite
1110 is composed of an upper nonwoven layer 1102, a lower nonwoven layer 1103, and
a plurality of mutually spaced apart elastic elements 1101 sandwiched therebetween.
The plurality of elastic elements 1101 are positioned centrally and are aligned generally
laterally, preferably generally perpendicular to a longitudinal centerline LL of the
elastic composite 1110. Preferably, the elastic elements 1101 are strands that are
tensioned when applied to the nonwoven layers 1102, 1103 so that the nonwoven layers
are later gathered by the elastic elements 1101 as the elastics relax.
[0049] FIG. 12 depicts one elastic composite 1210. In one respect, the elastic composite
1210 features the same basic construction as the previous elastic composite 1110:
a multi-layered, cross-directional elastic composite 1210 with a central elastic region
1204 and a plurality of mutually spaced apart elastic elements 1201 in the central
elastic region 1204. The plurality of elastic elements 1201 provides a central elastic
region 1204 that is clear of nonwoven layers. The elastic elements 1201 are, therefore,
exposed and define an open elastic area or region 1204. Furthermore, the elastic region
1204 is situated in between a first nonwoven composite carrier 1212, and a second
nonwoven composite carrier 1213 (hereinafter "carriers"). Each of carriers 1212, 1213
is preferably composed of a first or upper nonwoven layer 1202, a second or lower
nonwoven layer 1203, and the ends of cross directional elastic elements 1201 sandwiched
therebetween. In further designs, the upper and/or lower layers may employ a sheet
material other than woven (e.g., a film). The carriers 1212, 1213 are spaced in the
lateral or cross machine direction XX from a longitudinal centerline or machine direction
LL of the elastic composite 1210. The carriers 1212, 1213 are placed generally in
parallel relation with the centerline LL and provide the side border of the elastic
composite 1210. More preferably, the open elastic region 1204 is generally centered
about the composite centerline LL, and the elastic elements 1201 are equally spaced
and centered about the longitudinal centerline LL in generally perpendicular relation.
[0050] A comparison of the elastic composite 1210 with the earlier elastic composite 1110,
as depicted in FIG. 11, reveals at least a few important physical distinctions. A
primary feature of the elastic composite 1210 is that the elastic elements 1201 are
substantially uncovered or revealed between the carriers 1212, 1213. Moreover, the
three-layered composite, which is now referred to as carriers 1212, 1213, has a substantially
reduced width as compared to the width of the elastic region 1204. As will be further
described, the nonwoven carriers 1202, 1203 serve primarily to hold elastic elements
1201 in place (even if only temporarily) and facilitate further processing of the
elastic composite.
[0051] FIGS. 13A-13C are simplified illustrations used herein to describe a related, prior
art system and process for making the elastic composite 1210. Suitable components
for the system and apparatus shown in FIGS. 13A, 13B, are substantially the same as
or equivalent to those previously described herein (see FIG. 6). Moreover, the function
and operation of the components have also been described previously or are generally
known in the art. Accordingly, details as to the configuration and operation of these
components are not provided herein, but will be apparent to those skilled in the art.
[0052] A system 1350 suitable for the preferred embodiment includes a first nonwoven input
I1 (or other suitable material), a second nonwoven input I2 (or other suitable material),
and a web output O1 of a continuous elastic composite 1310. The first nonwoven input
I1 provides or feeds a web or roll (not shown) of a first nonwoven layer 1303 (or
other sheet of material), while the second nonwoven input I2 provides or feeds a web
or roll (not shown) of a second nonwoven layer 1303. The nonwoven layers 1302, 1303
ultimately provide upper and lower composite layers for each of the two carriers 1212,
1213 of the elastic composite 1310. The system 1350 further includes an output assembly
or reel (not shown) to receive the continuous web of elastic composite 1310 or output
O1 and, in some applications, direct the output O1 into a main manufacturing process.
[0053] Central to the system 1350 is a conveyor assembly 1309 for receiving, manipulating,
and conveying the nonwoven web inputs I1, I2 as well as the elastic composite output
O1. As described previously, the conveyor assembly 1309 preferably includes an upper
conveyor and platform (hereinafter upper conveyor 1314) and a lower conveyor and platform
(hereinafter lower conveyor 1315). Referring to FIG. 13C, the two conveyors 1314,
1315 are placed substantially adjacent each other but still sufficiently spaced apart
to allow independent movement. Preferably, the two conveyors 1314, 1315 have substantially
the same dimensions of length, L, width, W, and depth, D, and are positioned in parallel
relation such that one substantially mirrors the other. The vertical distance from
the top or outside of the upper conveyor to the bottom or outside of the lower conveyor
is the dimension "d". In most prior applications, this dimension, d, is equal to (twice
the width, W) plus the gap or distance between the conveyors.
[0054] The conveyor assembly 1309 is operatively associated with a suitable elastic element
applicator such as a spinning head assembly 1307 and spin head 1317 ("elastic spinners"),
as described previously. The spin head 1317 extends slightly over and about the ends
of the two conveyors 1314, 1315, and is configured to hold an "end section" of a continuous
elastic strand WW of elastic. Revolution of the spin head 1317 moves the end section
about a generally vertical plane VV and about the conveyor assembly 1309. The vertical
plane W preferably has a diameter that is just slightly less than the inside diameter
of the spin head 1317. The vertical plane intersects the conveyors 1314, 1315 and
further, webs moving on the conveyors 1314, 1315. As generally known, the two conveyors
1314, 1315 reciprocate such that the inside platform surface moves linearly toward
and past the vertical plane VV in a first web moving direction V1, before turning
as the outside platform surface. The outside platform surface moves linearly past
the vertical plane W in a second web moving direction V2 that is the reverse of the
first web moving direction V1. The path of the outside platform surface is spaced
outwardly of the path of the inside platform surface and in generally parallel relation
therewith.
[0055] Accordingly, a first nonwoven carrier web 1303 is directed to the conveyor assembly
1309. The conveyed web 1303 is then conveyed by the upper conveyor 1314 along the
first web moving direction V1 and through the vertical plane W. After arriving at
the end of the conveyors 1314, 1315, the nonwoven carrier web 1303 is passed onto
the top conveyor 1314 as shown in FIG. 13A, (or, onto the bottom conveyor 1315 in
alternate designs). As the nonwoven carrier web 1303 is conveyed through the vertical
plane W, a section of the elastic strand WW is applied across the nonwoven carrier
web 1303. Actually, the spin head 1317 revolves about the conveyors 1314, 1315 and
wraps a section of elastic strand WW about the two conveyors 1314, 1315.
[0056] Noting that the section of elastic WW is applied across the outside surface of the
lower conveyor 1315 as well, the moving conveyors 1314, 1315 draw continuous strand
WW away from the spin head 1317. The new substrate now consisting of the nonwoven
web 1303 and the elastics applied thereon is subsequently met by a second nonwoven
web 1304. The second nonwoven web 1302 is directed onto and in union with the upper
conveyor 1315a and atop the substrate of the first nonwoven web 1303 and elastics
applied thereon. As generally known, the second nonwoven carrier web 1304 is preferably
applied with a process adhesive upstream of the upper conveyor 1315a. The adhesive
is sufficiently applied to provide a secure bond between the two nonwoven carrier
webs 1302, 1303 and the elastics therebetween. In alternate embodiments, another suitable
process or means of bonding the layers and elastics may be employed (e.g., thermal
bonding, ultrasonic bonding, embossing, etc.)
[0057] Thus, a new composite or subcomposite is provided as a result of the union of several
components. This union includes: a first nonwoven web 1303 supported on the outside
surface of the upper conveyor 1314; a section of elastic strand WW applied across
the first nonwoven web 1303 multiple times; and a second nonwoven web 1302 applied
atop the first nonwoven web 1303 and the elastics applied thereon. As shown in FIG.
13A, the section of elastic strand WW extends outward from one side of the first non
woven web-second non woven web sandwich (on the upper conveyor 1314) (the "union"),
wraps around the lower conveyor 1314, and encircles by returning into the sandwich
or union through an opposite side. Prior to cutting, the section of elastic strand
WW actually encircles or enwraps both conveyors 1314, 1315 and the first nonwoven
web 1303 multiple times. Although the lower conveyor 1315 does not convey a sheet
of material in the traditional way, it does support and convey (in the web moving
direction V2) a series of elastic segments (of the elastic strand WW).
[0058] Referring specifically to FIG. 13A, this new composite is moved further in the second
web moving direction V2 by both the upper conveyor 1314 and the lower conveyor 1315.
The composite is specifically directed to a cutting or slitting mechanism ("slitter"
1334) positioned generally centrally and jutting into the path of the upper conveyor
1314. The moving composite intersects the slitter 1334 and is slit preferably longitudinally
across the center of the nonwoven-elastic-nonwoven sandwich ("elastic sandwich").
The elastic sandwich is divided to create the two carriers 1312, 1313 and an open
or exposed elastic region 1304 therebetween. The section of continuous elastic strand
WW, which had encircled or enwrapped the conveyors 1314, 1315, is also severed to
create separate elastic segments 1301. The resulting composite 1310 moves forward,
which causes the two carriers 1312, 1313 to slide downward off the conveyors 1314,
1315, as shown in FIG. 13A. Preferably, the carriers fall and unwrap below the conveyor
assembly 1309. By slitting the previously enwrapped elastic composite, the resulting
composite output O1 may be readily removed from the conveyor assembly 1309 and further
received for storage or post-processing.
[0059] In one respect, an elastic composite 1210 is provided having an exposed elastic construction
or open elastic region 1204 formed by the plurality of mutually spaced apart elastic
elements 1201, as shown in FIG. 12. In this composite 1210, the elastics 1210 of the
exposed or open elastic region 1204 are independent or clear of any nonwoven layers.
The elastic elements 1201 extend generally laterally from one carrier 1212 to the
second carrier 1213, and across the longitudinal centerline LL. The elastic elements
1201 are therefore generally oriented along the cross-machine direction, and may be
referred to as cross-directional elastics. Interestingly, the width of the open elastic
region 1204 (i.e., the lateral spacing between the two carriers 1212, 1213) is primarily
dependent on two processing parameters. Firstly, the width of the open elastic region
1204 is dependent on the total circumference of the conveyor assembly 1309, i.e.,
the circumference about the upper conveyor 1314 and the lower conveyor 1315. This
circumference is also substantially equal to the travel length of the section of elastic
strand WW about the conveyor assembly 1309 upon one revolution of the spin head 1317.
This length is the sum of the width W of the upper conveyor 1314, the width W of the
lower conveyor 1315, and twice the distance, d, between the upper surface of the upper
conveyor 1314 and the lower surface of the lower conveyor 1315. Secondly, the width
of the open elastic region 1204 is dependent on the tension applied to the elastic
strand WW when the strand is applied about the nonwoven web 1303. If a relatively
higher tension is applied, the width of the open elastic region 1204 in the relaxed
state will be decreased.
[0060] The width of the open elastic region 1204 is also dependent on and provided by the
extension state of the elastic elements when the measurement is taken. Generally,
the important reference measurements are those made when the elastic elements are
fully relaxed (extension factor equals 1x), and measurements taken when the elastic
elements are fully extended (typical extension factor equals 4x to 6x, depending on
the type of elastic used). FIG. 14 illustrates an elastic composite 1210 in a relaxed
state, i.e., no tension is applied to the elastic. To the right of the relaxed elastic
composite 1210 is a depiction of the elastic composite 1210' under tension,
i.e., the extended state.
[0061] Example 1: In one design, the width of open elastic region may be approximated as follows:
Given, conveyor width, W= 100mm;
distance, d, from upper surface of upper conveyor to lower surface of lower conveyor = 40mm;
extension applied to continuous elastic strand = 4x;
full extension of elastics = 5x.


[0062] Example 2: In another design, the width of the open elastic region is increased by reducing
the extension applied to the elastic strand as it is applied to the nonwoven carrier
web. The circumference of the conveyor assembly is also increased by increasing the
separation of the upper and lower conveyors. In some suitable systems, one of the
conveyor platforms is simply moved further from the other platform. It should also
be noted that one of the conveyors is not required to move a sheet of material, but
only the elastic wrapped about it. This allows for use of conveyors different from
the generally flat platforms or belts commonly used to support a sheet of nonwoven.
[0063] Given, conveyor width, W =
100mm,
distance, d, from upper surface of upper conveyor to lower surface of lower conveyor = 100mm,
extension applied to elastics = 1.5x,
full extension of elastics = 5x.


[0064] Examples 1 and 2 above illustrate that the width of the open elastic area may be
adjusted by making small changes to the applied extension of the elastics and to the
dimensions of the conveyor assembly. In certain designs, the tension is determined
by the feed rate of the elastic strands into the spin head and the frictional characteristics
of the feeding and spinning process. The circumference can be varied mechanically
by changing the distance between the upper and lower conveyors.
[0065] Notably, the elastic composite 1210 is characterized by mutually spaced apart, cross-directional
elastic elements 1201 that extend laterally between the first and second carriers
121, 1213 and in transverse relation with the machine direction of the elastic composite
(LL). Each of the layers 1202, 1203 of the carriers 1212, 1213 preferably extends
generally longitudinally in generally parallel relation with the machine direction
LL and has a lateral width that is substantially less than a lateral width between
the first and second carriers 121, 1213 (across the open elastic region 1204). In
a further aspect, the elastic elements 1201 of the open central elastic region 12104
are "discrete disconnected segments of one elastic strand". This means that the elastic
elements 1201 originate from the same elastic strand and are, in fact, severed sequentially
from the same elastic strand while that strand is in a generally uniform state of
tension or application (
e.g., secured in tension between adhered nonwoven layers). Being discrete disconnected
segments of one elastic strand further means that the elastic elements have substantially
identical material and mechanical properties (particularly, dimensions, strength,
and elastic properties). The inclusion of such elastic elements can offer benefits
in the ultimate elastic composite as well as the processes in the making of the elastic
composite. For example, having uniformity and consistency in the plurality of elastic
elements facilitates handling of the elastic composite, provides a cleaner and more
aesthetically pleasing gathering in the ultimate disposable absorbent article, and
may also produce a better quality product with less flaws.
Applications - Post Processing
[0066] A variety of applications for the cross directional elastic composite 1210 and output
composite 1303, O1 described above are contemplated. These applications include direct
incorporation of the elastic composite 1210 (having the open elastic region) as a
component in a disposable absorbent article and particularly, into a process of making
the article. For example, the elastic composite 1210 may be integrated as a wide elastic
waistband of a diaper type product. The elastic composite 1210 may also be applied
as a body encircling elastic component for training pants.
[0067] A cross directional elastic composite with open elastic region is also well suited
for further processing prior to integration into a disposable absorbent article. FIGS.
15 and 15A depict an exemplary product of further processing of elastic composite
1310. FIG. 15A depicts an elastic composite in the form of an elastic laminate 1511
derived from a method according to an embodiment of the disclosure. The laminate 1511
includes an upper nonwoven layer 1502, a lower nonwoven layer 1503, and a plurality
of tensioned elastic elements 1501 sandwiched therebetween. The laminate 1511 further
includes first and second carriers 1512, 1513 serving as the side borders of the laminate
1511. The elastic laminate 1511 may yield, in turn, several multi-layered, cross directional
elastic composites 1510. These elastic composites 1510 are also in a form that is
particularly suited for further processing and ultimately, for fastening tape and
elastic side panel applications. FIG. 16 illustrates an exemplary system 1601 and
process that receives the elastic composite web output O1 and further processes the
web O1 to produce the elastic laminate 1511 and the multilayered elastic composites
1510. In particular, the exemplary system 1601 and process illustrates the flexibility
of various embodiments of the disclosure to create cross-directional elastic sheet
materials of varying width.
[0068] In accordance with one method, the output O1 (continuous web of elastic composite
1310) of system 1350, as described in respect to FIG. 13, is received by the present
system 1601 and more particularly, by a conveying device, referred to hereafter as
extender 1602. The extender 1602, shown in further detail in FIG. 17, secures the
continuous web O1 along each carrier 1312, 1313 and stretches the open elastic region
1304 to a desired width, while moving the web O1 forwardly in the system 1601. The
extender 1602 includes a pair of identical reciprocating components 1604, 1605. The
reciprocating components 1604, 1605 may employ a wheel, belt or chain based system
to reciprocate. As shown in FIG. 17, the two reciprocating components 1604 are situated
upright and spaced apart from another at an angle such that a lateral space XX between
the two expands along the web moving direction. The reciprocating components 1604,
1605 are adapted with engagement means 1607 for securing the web O1 preferably at
the carriers 1312, 1313. The engagement means can be found in the form of pins, mechanical
grips, or the like. The web O1 is stretched as the web O1 is moved forwardly between
the two components 1604, 1605 and as the lateral space XX expands. In this way, the
extender 1602 extends the width of the open elastic region 1304 to a target width,
and carries the elastic web O1 from its original relaxed state to a desired extended
or tensioned state (O1').
[0069] The tensioned elastic composite O1' is then fed to a laminating stage, wherein a
lower nonwoven web 1503 is continuously directed to the web O1' from below and an
upper nonwoven web 1502 is continuously directed to the web O1' from above. Prior
to reaching the web O1', hot melt adhesive is applied to each of the nonwoven webs
1502, 1503 using suitable adhesive application equipment 1616. Thereafter, the lower
nonwoven web 1503 is applied to the "underside" of open elastic region 1504' of the
web O1' and the upper nonwoven web 1502 is applied to the "topside" of the open elastic
region 1504'. The applied adhesive ensures proper bonding between the nonwoven layers
and the tensioned elastic elements. The resulting laminate 1511 includes, therefore,
an upper nonwoven layer 1502, a matching lower nonwoven layer 1502, 1503, a pair of
carriers 1512, 1513 providing the side borders of the laminate 1511, and a plurality
of mutually spaced apart elastic elements 1501 extending between the carriers 1512,
1513 and sandwiched between the nonwoven layers 1502, 1503. As compared to the output
web O1, the elastic elements 1501 are now in an extended state, but remain laterally
oriented, thereby imparting cross-directional elasticity to the laminate 1511.
[0070] Notably, the two carriers 1512, 1513 serve a handling function during the process.
The carriers 1512, 1513 ensure that the configuration of elastic elements is maintained
as the webs O1, O1' are processed. The carriers 1512, 1513 also provide a solid base
for the components of the system 1601 to secure and handle (
e.g., convey and stretch) webs O1, O1'.
[0071] As shown in the exemplary diagram of FIG. 16, the resulting laminate 1611 is directed
forward to a slitting mechanism 1634. In this embodiment, the slitting mechanism(s)
includes five slitters that sever the carriers 1512, 1513 from the laminate 1511 and
slits the laminate 1511 into four separate webs of yet another cross-directional elastic
material or multilayer elastic composite 1510 according an embodiment of the disclosures.
The slitters 1634 are positioned in alignment with slitting lines SS along the web
O1'. In this embodiment, the set of five slitting lines SS is equally spaced apart
and include slitting lines SS adjacent the carriers 1512, 1513. As a result, the slitters
1634 divide the laminate 1511 into four separate but identical webs O2 of cross directional
elastic composite 1510. Each of the four webs O2 is then directed as web output O2
to a reel or spool. Further, the web output O2 of elastic composite 1510 may be packaged
for easy handling and for further processing, or fed directly into a manufacturing
process.
Elastic Composites Having Dead Zones
[0072] The preferred elastic composite may be equipped with a pair of non-elasticized regions
or dead zones, the utility of which has already been described. As generally known,
the dead zones are preferably situated on either lateral side of a central elastic
region having an elastic construction (as discussed previously). Various ways are
envisaged to create the dead zones within methods of making the elastic composite
according to the disclosure. In one exemplary method, an adhesive pattern is applied
to the nonwoven web input. The adhesive pattern is selectively applied so that adhesive
is provided only to areas of the nonwoven web wherein the elastic strands are to be
retained.
[0073] To illustrate, FIG. 18 shows an elastic composite laminate 1511 generated by a process
such as that described above in respect to FIG. 16 and in a stage prior to passage
of the web of the laminate 1511 through a set of slitting mechanisms. Tensioned elastic
elements 1501 are sandwiched between the upper and lower nonwoven webs 1502, 1503
and extend between the carriers 1512, 1513. In this example, adhesive is applied only
to prescribed areas of nonwoven webs 1512, 1513 ("adhered areas"), which areas are
indicated as shaded areas A in FIG. 18. The adhesive application means 1616 described
previously are precisely positioned over the path of the webs 1512, 1513 that correspond
to the shaded areas A and operated to apply adhesive only to these areas A. The areas
between the shaded areas A (
i.e., "non-adhered areas" indicated as un-shaded areas B in FIG. 18) in the resulting
laminate 1511 are clear of adhesive such that the portions of the elastic elements
1501 found therein remain loose. As indicated by slitting lines SS, slitting mechanisms
provided downstream are aligned with the center of these non-adhered areas B. As the
web of the laminate passes the slitters, the elastics in the non-adhered areas B are
cut. Furthermore, the non-adhered areas B are divided into two sections. Each half
section provides, thereafter, one non-elastic or dead zone of the multi-layered elastic
composite 1510.
[0074] In the illustrated design, a non-adhered area B is located adjacent each of the two
carriers 1512, 1513 and a slitting line SS is aligned along the inside of the carrier
1512, 1513. As a result, the carrier 1512, 1513 is cut and removed from the web during
the slitting process. The formerly adjacent non-adhered area B remains as a dead zone
of the resulting cross-directional elastic composite.
[0075] FIG. 19 illustrates yet another laminate 1911 (an elastic composite). The illustrated
laminate 1911 helps explain an alternate method of making a cross directional elastic
composite featuring a pair of dead zones and a central elastic region therebetween.
According to this method, the step of applying an upper (or lower) nonwoven web 1902
is modified by providing several folds 1940 in the nonwoven web 1902. A suitable folding
sub-process is one substantially equivalent to the sub-process described in respect
to FIGS. 6-10, and are now known in the art. The web 1902 is pre-folded to provide
an excess folded section 1940 in the tensioned elastic composite O1' and in the resulting
laminate 1911, as shown in FIG. 19 for the use of multiple folding boards. A slitting
line SS may be aligned with the center of each folded section 1940 much in the same
manner as described above in respect to FIG. 18. In the slitting step, each folded
section is divided into two separate folded sections and the elastic elements beneath
the fold are severed. For each resulting individual elastic composite, the two folded
sections are then unfolded to reveal dead zones on each side of a central elastic
region.
[0076] FIG. 13D depicts an alternative system that employs or receives into the conveyor
assembly 1309 two additional input webs of non-woven (I3 and I4) to double the output
of the inventive system and process as described previously in respect to FIGS. 13A-C.
As before, non-woven web input I1 is initially directed in between the upper and lower
conveyors 1314, 1315, before being redirected and conveyed atop the upper conveyor
1314 whereon it receives the spun elastic WW. Then, the second nonwoven input I2 is
applied over the transversely applied elastics WW and nonwoven input I1. Nonwoven
input web I3 is also directed in between the upper and lower conveyors, in a manner
similar to the conveyance of I2. The non-woven input I3 is, however, redirected and
conveyed upon the lower conveyor 1315. With the nonwoven input I3 moving in the reverse
direction on the lower conveyor 1315, the spin head 1317 applies elastic WW onto and
about both conveyors 1414, 1315 and both I1, I3 during each revolution. With the elastics
applied generally transversely thereupon, the fourth feed of nonwoven I4 is applied
to the sub-composite of the non-woven I3 and elastic elements. Two multi-layer elastic
composites or sandwiches are conveyed by the upper and lower conveyors 1314, 1315,
respectively, while joined together by the continuous elastic strand WW. At this point,
a slitter or other cutting mechanism 1334 placed in the path of each of the two composites
preferably slits the composite centrally, thereby producing two separate but substantially
identical carriers (as shown in FIG. 13D). With the slitters 1334 cutting the nonwoven
webs centrally on the upper and bottom conveyors, the two resulting webs of elastic
composite outputs O1, O2 conveniently slides to either side of the conveyor assembly
1309 and is received for further processing.
[0077] In some respects, FIGS. 20-38 illustrate an elastic absorbent assembly (or the making
of) that is made by a process that borrows from or employs modified aspects of the
methods earlier described of making the elastic composite of FIGS. 13-19. Moreover,
certain aspects unique to the present disclosure may be readily merged with or practiced
in conjunction with at least parts of systems, methods, and products previously described.
In accordance with the present disclosure, an elastic absorbent assembly is provided
particularly suited for incorporation into a disposable absorbent garment. Referring
first to FIGS. 20A and 20B and in accordance with one embodiment, the elastic absorbent
assembly 201 has a top layer N1, a base layer N2, and an elastic construction EC disposed
in between, or sandwiched by, the top and base layers N1, N2. (MD) In FIG. 20, the
elastic construction EC is composed of plurality of spaced apart elastic elements
E (hidden but represented in dash lines) forming, with the base and top layers N1,
N2, a plurality of encapsulating spaces or preferably elongated capsules C, wherein
absorbent material S is disposed. "Encapsulating" - has defied void space between
N1 wherein materials such as a.m. may be retained. Preferably, the top and base layers
N1, N2 are nonwoven and the absorbent material includes, but is not limited to, superabsorbent
polymer particles S.
[0078] The elastic absorbent assembly 200 may be provided as the product of a sub-process
(of making elastic absorbent assemblies) and delivered or merged with a process of
making a disposable absorbent article. For example, the elastic absorbent assembly
200 may be delivered onto a chassis for an unfinished diaper 201 prior to application
of a topsheet over the elastic core assembly 200. Preferably, the elastic absorbent
assembly 200 is delivered as a self-supporting core construction with the capsules
C confining SAP therein and the side edges (at BO) and end edges of the assembly sealed
or otherwise secured to prevent SAP escape during manufacturing. See elastic core
assembly 200 with the outline or contour of longitudinally directed SAP-containing
capsules C shown in each of FIGS. 2, 2A-2C.
[0079] As shown, the elastic construction EC is preferably provided by a plurality of spaced
apart elastic filaments E, strands, and the like. The filaments E are preferably secured
to one or both of the top and base layers N1, N2 at spaced apart or intermittent bond
sites or points B, thereby forming the encapsulating spaces C. The bond sites B may
be effected using adhesives, ultrasonic bonding, heat induced bonding, embossing and
the like. In the core construction or assembly, the elastic filaments E are directed
transversely to the direction of the elongated encapsulating capsules C, which direction
of the elastic elements being the lateral and cross-machine direction CD and the direction
of the capsules being the longitudinal and machine direction MD. Accordingly, the
elastic core assembly 201 may be described as being cross-directionally elasticized
due to the elasticity of the filaments E. Between the bond sites B mutually securing
the top and base layers N1, N2 and the elastic filaments E, the two layers N1, N2
may be un-bonded or bonded. Thus, the two layers N1, N2 may be bonded continuously
at laterally spaced, preferably continuous bond lines B that also hits or crosses
most, if not all, of the spaced apart elastic filaments E at the aforementioned bond
points B.
[0080] In the embodiment of FIG. 20, adhesive is applied linearly and continuously to adhere
the layers N1, N2 substantially continuously, including at and with the elastics E
at the mutual intersection of the three elements (E, N1,N2). A plurality of said continuous
bond lines B are disposed spaced apart in the lateral or cross direction, which spacing
generally dictates, at least in this embodiment, the width of each capsule C. See
also FIG. 20B. At the longitudinal side edges or margins of the composite 200, the
nonwoven layers N1, N2 are also secured or sealed by a bond BO (preferably by adhesive
or ultrasonic bonding). As further described herein, such adherence between the elastics
E and one or both layers N1, N2 may be effected while the elastics C are in an extended
or stretched mode. As the elastics E relaxes, the adhered layer(s) shirrs and the
capsule C may sag or bulge outwardly (above or below according to the view of FIG.
20B) with excess material. With the elastics E secured intermittently to both layers
N1, N2 and the bond lines B continuously attaching to the layers N1, N2 together,
the capsules C have a rounded cross section. The capsule C also takes on an elongated,
almost tubular shape.
[0081] Furthermore, the spaced apart bond lines B and top layer N1 form valleys V between
the capsules C and above the shirred nonwoven layer N1. In further embodiments, one
or more of the valleys V may be deposited with absorbent material that may or may
not be the same as the absorbent material S situated in the capsules. In further embodiments,
only the valleys near the center of the core assembly C and\or in the target receiving
areas of the diaper, such as the center and near, rear center of the crotch region
of the diaper 200, may be deposited with additional absorbent material (i.e., SAP).
In further embodiments, another sheet layer is provided over the top layer N1 and
the valleys V thereon. This creates additional encapsulating spaces for absorbent
material.
[0082] FIGS. 21A and 21B provide an end cross-sectional view of another embodiment of the
elastic core assembly 200, wherein like reference numerals are used to indicate like
elements. Elastic E is secured to each of a top nonwoven layer N1 and a base nonwoven
layer N2 at bond sites B. Elongated capsules C are formed between longitudinally aligned
series of bond sites B. The capsules C are provided with SAP that initially fills
at least the void of the capsule C below the elastic. Advantageously, the capsule
C has sufficient capacity, and void space, to allow for expansion of the SAP aggregate
S during liquid intake. The additional void space is typically provided at the upper
part of the capsule C, as most SAP particles S fall and rest on the bottom nonwoven
layer N2. In the embodiment of FIGS. 21A-21B, the bond sites are generally wider and
correspond to SAP-free lanes L0 (during the process of making the composite). Also,
the resulting valleys V are wider and flatter, and can accommodate more absorbent
material for storage as needed.
[0083] FIG. 21A illustrate the state of the elastic core assembly 200 upon securement of
the elastics E with the top and base layers N1, N2. The elastics E are in a stretched
state, while the top layer N1 is in an extended, generally flat state. The base layer
N2 may also be referred to as being in a relatively stretched state, but, in this
embodiment, is wider (in lateral direction) than the top layer N1 and provided with
greater slack. Even in the stretched state, the base non woven layer N2 has sufficient
slack to bulge downward and create void space for the capsule C. This void space accommodates
the SAP particles S below elastic E. When the elastics E are released and then reverts
to a relaxed state, as illustrated in FIG. 21B, the top nonwoven layer N1 contracts
and urges material upwards. This action creates more void space above the elastic
C and presents an upper bulge to the capsule C. As well, valleys V are formed between
the capsules C. During wear, the elastic core assembly 200 may take on a slightly
stretched profile or configuration, somewhere between FIGS. 21A and 21B.
[0084] In further embodiments, the different capsules C may vary in size or SAP capacity.
For example, the capsules C in the central region may be made wider (than capsules
outward thereof) due to greater lateral spacing of the bond sites B. The capsules
C in the central region may be provided with greater capacity due to a wider exposure
of nonwoven material N1, N2 and greater slack in the reduced N1, or L. Furthermore,
the larger cells may be deposited with greater volume of absorbent material. Further
yet, certain of the capsules may be deposited with different constituents having differing
properties, as further described below.
[0085] FIG. 21C provides an end cross-sectional view of another embodiment of the elastic
core assembly 200, wherein like reference numerals are used to indicate like elements.
In this embodiment, two (or more) space apart bond sites B1 are provided to secure
the base layer N2 (or top layer N1 in other embodiments) to the elastics E and top
layer N1. The spaced apart bond sites B1 are preferably continuously extending bond
lines (such as adhesive) and form an unsecured gap over the SAP-free lanes L0. After
bonding the base layer N2, top layer N1, and elastics E together, tension on the elastics
E is released. The relaxing elastics E contracts the top layer N1 and base layer N2,
as shown in FIG. 21C. The material of the base layer N2 contracts and gathers at the
gap to form void spaces V2 that, together, provide channels or tubes V2 extending
adjacent and parallel with the capsules C. Notably, these channels provide SAP-free
and hot-melt free passages for fluid flow. In certain embodiments, the tubes V2 may
be of a dimension suitable for capillary flow to promote transport of fluid in the
longitudinal direction of the core assembly.
[0086] In the embodiment of FIG. 21C, the elastics E and the nonwoven layer N1 are bonded
with solid bonds, B2 in the gap or SAP-free lanes L0. The bonds B2 may, however, be
placed of spaced-apart bond points such as the bond points B1.
[0087] FIGS. 22A -22C illustrates another embodiment of an elastic core assembly 201, according
to the present disclosure, wherein like reference numerals are used to indicate like
elements. The plan view of FIG. 22A shows the continuous bond line B, preferably provided
by strips of adhesive, and the resulting wider SAP-free lanes L0. In this embodiment,
the base or bottom nonwoven layer N2 is secured to the elastic E while in an extended
and generally flat state (as opposed to the top nonwoven layer N1 being so). The end
cross-sectional view of FIG. 22B shows the profile of the elastic core assembly 200
in the stretched state, wherein the base layer N2 is flat but the slacked top layer
N2 provides a void space for SAP storage. FIG. 22C then shows the profile of elastic
core assembly 200 in the relaxed state, as commonly found when the diaper 201 is opened
and ready for wear. During wear, the elastic core assembly 200 may be take on a slightly
stretched profile or configuration, somewhere between FIGS. 22A and 22B.
[0088] FIG. 23 is a plan view of an alternate embodiment of an elastic core assembly 201
according to the present disclosure, wherein like reference numerals are used to indicate
like elements. In this embodiment, the nonwoven layers N1, N2 are not secured continuously
along a longitudinal bond line. Instead, the nonwoven layers are secured only at bond
sites B0 with elastics E. As a result, the capsules C are generally open to adjacent
capsules and in fluid communication therewith. Fluid and SAP can, therefore, travel
laterally (as well as longitudinally) from capsule C to capsule C, except at the bond
sites B. In the plan view, valleys or depressions V are shaped nearly circular or
even near diamond shape at and about the bond sites or bond points B. In comparison
to the other embodiments, the capsules C are less defined, at least in the machine
or longitudinal direction. The capsules C are not isolated and segregated from one
another, as illustrated in FIGS. 20-22, and there is fluid communication and travel
in the lateral direction. In one respect, a fluid channel is created in the cross
direction and between spaced apart elastics. In another respect, the capsule C may
also be characterized functionally and structurally as being directed laterally or
both laterally and longitudinally. In yet another characterization, the capsules C
may be characterized as being replaced or being comprised of individual cells or pockets
C'. Each of these pockets C' are substantially open and bounded (and formed) by four
spaced apart bond sites or points, and two segments of elastics.
[0089] An elastic absorbent assembly or composite according to various embodiments supports
and maintains absorbent materials at desired locations on the diaper 201. The absorbent
material is primarily and preferably superabsorbent particles and additives that are
confined between facings provide by sheet materials (i.e., nonwovens) and with elastic
filaments or strands arranged within the assembly to provide stretch and recovery
to the composite. Each strands is intermittently attached to at least one of the top
layer and the base layer at spaced apart attachment points along the length of the
strand such that attachment of the plurality of elastic strands with the top or bottom
layer at said attachment points form spaced apart ridges between pairs of spaced apart
attachment points. The elastic filaments are arranged appropriately to provide CD-stretch,
MD-stretch or both MD and CD stretch.
[0090] Such an elastic absorbent composite has good flexibility, elastic stretch and garment-like
properties that enables good fit with the body of the user. Features of the absorbent
composite include creation of absorbent-containing tubes or capsules that can direct
fluid along its length and absorbent-free channels that can allow fluid to flow along
its length and hence provide another path for delivering the liquid to the absorbent
material contained in the capsules. Additionally, composites with a surface topography
that can be varied can be produced. Such topography can be produced by varying the
spacing of the elastic filaments to vary the protrusion height established when the
elastic is allowed to relax. The topography can be used to reduce side leakage, back
or front waist leakage. For example, higher protrusions along the sides of the absorbent
core can provide a barrier for side leakage. (See e.g., FIG. 32A). It is also contemplated
to vary the absorbent loading is each channel to achieve a SAP profile that can enhance
the leakage performance of an absorbent core made from this material. For example,
an elastic core assembly with a profile providing higher absorbent content adjacent
the side edges can reduce side leakage.
[0091] The elastic core assembly may be formed in several ways. FIG. 24A is a simplified
illustration of a system and method of making the elastic core assembly 200, according
to the present disclosure. FIG. 24B is an isometric view of an exemplary system, in
operation, for use in making the elastic core assembly (wherein like reference numerals
are used to indicate like elements). The exemplary process entails conveying a shaped
substrate S2 or web of nonwoven sheet N2, and depositing thereon, populations of absorbent
material. The absorbent material is deposited onto one or more target locations on
the moving substrate S2. In this embodiment, a hopper 2401 is employed to dispense
and apply SAP particles S with the aid of gravity along spaced apart locations or
lanes on the moving substrate S2. A web of an elastic composite O1 with spaced-apart
elastic strands E is then applied over the SAP-supplied substrate S2. The elastic
composite O1 is conveyed and applied while secured in a stretched or tensioned state
and engages the substrate S2 of nonwoven N2 co-incidentally or linearly (i.e., moving
along the same linear and planar direction at engagement), as shown also on FIG. 24B.
Notably, the elastic composite is secured in tension and driven by way of the carriers
(see earlier FIGURES and accompanying descriptions). After engagement, the plurality
of elastics E are disposed in the cross-machine direction in the resulting elastic
composite SO1 (of S2 and O1). See FIG. 24B. A second substrate S1 of nonwoven sheet
N1 is then applied on the resulting un-finished elastic composite SO1 to produce the
elastic core assembly SO2 formed with a plurality of capsules C.
[0092] The shape of the capsules C may be dictated, at least partly, by the manner and pattern
by which the elastics E and nonwoven layers N1,N2 are mutually secured. In the process
according to FIG. 24, an adhesive applicator 2402 is positioned to apply adhesive
W to the moving substrate S1 at predetermined lanes, lines or spots, prior to the
substrate S1 engaging substrate S2 and elastic composite O1. Referring to FIG. 24B,
a multi-port adhesive applicator may be operated to apply lanes of hot melt adhesive
W prior to the substrate S1 being rolled upon unfinished elastic composite SO1. The
resulting adhesive lanes coincide with SAP-free lanes L0 on substrate S2 and away
from the lanes of SAP S. The resulting elastic absorbent composite SO2 remains tensioned
as it moves forward from roller R2 and before moving past cutters K. The severing
edges of cutters K are positioned inwardly of the carriers to cut through the elastic
composite SO2, including through elastics E. As a result, the elastics E are released
from the carriers and from tension, and the resulting elastic absorbent composite
200 contracts to finished form. As shown in FIG. 24B, the contracted elastic absorbent
composite 200 is provided with a plurality of tube-shaped capsules C containing SAP.
[0093] A primary but optional input (designated by Box 2403) to the process of FIG. 24 is
a base nonwoven N2 that is shaped with longitudinally-oriented channels or grooves.
The channels are shaped and positioned to receive the SAP particles. The substrate
S2 may be shaped by folding, corrugating or having the sheet conform to a shaped surface.
FIG. 25 illustrates such a sub-process of shaping and providing substrate S2 as input
to the exemplary process. In this sub-process, the nonwoven substrates S2 is passed
through a shaped plate or fingers that jut out and, by force, form corrugations on
the passing substrate sheet. The sub-process FIGS. 27A-27C illustrates exemplary roller
combinations suitable for shaping or conforming the substrate S2 as desired. The interlocking
teeth on the rollers form corrugations on the nonwoven sheet that is passed between
the rollers.
[0094] FIGS. 26A and 26B illustrate two suitable substrate S2 configurations. The substrate
S2 in FIG. 26A may be configured preferably employing a conforming process such as
that illustrated in FIG. 25. The substrate S2 in FIG. 26B may be configured preferably
employing a similar conforming process wherein the surface of the nonwoven sheet is
forcibly shaped. In the alternative, the substrate S2 of FIG. 26B may be pre-formed
by a folding sub-process. Suitable folding sub-processes may be similar to those previously
described herein. The substrate S2 is sourced from a nonwoven sheet that is conformed
with a plurality of channels or grooves G in the machine or longitudinal direction.
The substrate S2 also features a plateau or lane (SAP-free lane) L0 between the grooves
G. Product design requirements may specify a desired depth of the grooves G and width
of the lanes L0.
[0095] Referring again to FIG. 24, absorbent material such as superabsorbent particles may
be supplied from hopper 2401 or set of SAP dispensers above the substrate S2, while
the substrate S2 is moved forwardly in a generally horizontal disposition. The SAP
particles S will fill the grooves G preferentially, while the SAP free lanes L0 are
preferably maintained clear of SAP. A CD-arranged assembly of stretched filaments
is simultaneously conveyed linearly toward and atop the moving SAP-filled substrate
S2. A suitable assembly of elastic filaments is the elastic composite O1 produced
by the process illustrated in FIG. 28 and described previously (in respect to FIG.
13 for example). The elastic composite O1 is overlaid on the SAP-filled nonwoven substrate
S2, with the elastic filaments disposed in the cross-machine direction and across
the SAP-filled grooves.
[0096] FIGS. 29A and 29B each depicts, in simplified form, an alternative system and process
for making the elastic core assembly 200 (wherein like reference numerals are used
to indicate like elements). In the system and process variation of FIG. 29A, the SAP
dispenser 2401 is positioned downstream of engagement between the elastic composite
O1 and substrate S2, and applies SAP S to the substrate S2 in laterally-spaced apart
strips. The substrate S2 in this example may or may not be preformed or corrugated.
If pre-formed with grooves, the strips of SAP are conveniently applied (e.g., dropped)
into the grooves. Alternatively, strips of adhesives may be pre-applied on substrate
S2 at laterally-spaced locations corresponding to SAP applications. In this way, the
SAP strips are maintained in the designated lanes during manufacturing. In another
variation, the SAP may be pre-mixed with adhesive (e.g. HMA) prior to the dispenser
2401 applying adhesive-laden absorbent material S onto the substrate S2 in the designated
lanes.
[0097] Referring again to the embodiment of FIG. 29A, substrate S1 is pre-applied with strips
of adhesive W as it is conveyed toward substrate S2 and elastic composite O1. Engagement
between substrate S1 with substrate S2 and the elastics adheres these components together.
Thereafter, tension on elastic composite O1 may be released and substrates S1 and
S2 contracts with elastics E. Contraction creates excess material or slack in the
substrates S1, S3, which results in expanding and shaping the desired capsules C.
With substrate S2 and S1 in adherence, SAP is confined in the capsules C.
[0098] FIG. 29B depicts, in simplified form, an alternative system and process for making
the elastic core assembly 200. In this system and process variation, the SAP dispenser
2401 is positioned downstream of engagement between the elastic composite O1 and substrate
S2'. Further, an adhesive applicator is positioned upstream of engagement between
the elastic composite O1 and Substrate S2, and applies spaced apart strips of adhesives
on the substrate S2. Accordingly, when the elastic composite O1 engages with the substrate
S2 in stretch mode, the elastic composite O1 adheres to the substrate S2. When elastic
composite O1 is later released, it contracts the substrate S2 and, as pre-designed,
creates downwardly urging void space with the excess material. In such variations,
conforming or corrugating of the substrate S2 may not be needed for creating the capsules
C. The SAP dispenser is positioned downstream of where the elastic composite is released
and after the void spaces are formed. SAP can then be deposited onto the void spaces
or capsules C.
[0099] Referring again to FIG. 29B, adhesive is applied on substrate S1 prior to engagement
with substrate S2 and elastic composite O1. When continuous lines of adhesive are
used and aligned with sap-free lanes on substrate S2, substrate S1 adheres to both
elastic composite O1 and substrate S2. Elastic composite O1 may be maintained in the
same stretched state after engagement with substrate S2 and during engagement with
substrate S1. Upon release, elastic composite O1 contracts with both substrates S1,
S2. The substrates S1, S2 relaxes and with the excess material, expands the profile
of resulting capsule C. In a variation, elastic composite O1 is released to some degree
after engagement with substrate S2 and substrate S1 is applied generally flatter and
extended over SAP-filled and semi-contracted substrate S2 and semi- relaxed elastic
composite O1. Upon full release of elastic composite O1, substrate S1 will contract
and substrate S2 will contract further. The resulting profile of the elongated capsules
C will project predominantly downward.
[0100] As reflected in the discussion above, the degree of release of elastic composite
O2 at various points or stages in the process is a design variable that can be utilized
to achieve different shapes of the capsules, different properties and different functionalities.
The degree of slack on the substrates S1, S2 prior to engagement with elastic composite
O1 is also design variable that may be varied in conjunction with the degree and process
point of tension release (of elastic composite). Further yet, the pre-forming of substrate
S1 and\or S2, including the creation of SAP-free lanes of specific dimensions, may
also be useful in achieving design objectives.
[0101] FIG. 30 illustrates three possible configurations of the substrates S1,S2 in making
the elastic core assembly 201 (wherein like reference numerals are used to indicate
like elements). The first configuration of substrate S1, S2 (on the top) is corrugated
with wider SAP-free lanes L0, while the second or middle configuration of substrate
S1, S2 is not equipped with any SP-free lanes. The third configuration of substrate
S1, S2 is provided with intermediate size SAP-free lanes L0. The figures on the illustrate
the varying SAP-loading capacities of the substrate. The first configuration has the
wider SAP-free lanes but sacrifices SAP loading capacity.
[0102] FIGS. 30A and 30B provides additional simplified illustrations of an elastic core
assembly 200 (wherein like reference numerals are used to indicate like elements)
in the stretched state (FIG. 30A) and then the relaxed state (FIG. 30B). The embodiment
of FIG. 30 provides another example of core assembly designs that achieve a desired
dynamic and\or desired stretched and un-stretched configurations. Substrate S1 of
nonwoven N2 is pre-applied with stripes of adhesives located to align with the SAP-free
lanes LO in substrate S2. The substrate S1 is then applied over the sub-assembly of
substrate S1 and elastic composite O1, such that elastic filaments E are bonded in
discrete points or areas to both the bottom and top sheets N1, N2. This merger forms
the CD-stretchable absorbent composite 200 in its relaxed state (FIG. 30B). The extent
of stretch in the composite 200 is determined by the amount of stretch in the elastic
filaments when bonded and fixed to the nonwoven facing sheets N1, N2 from its relaxed
state.
[0103] FIGS 32A and 32B illustrate alternative embodiments of the elastic core assembly
200 wherein the spacing between spaced part bond points on the elastic E are varied
to achieve a desired profile (wherein like reference numerals are used to indicate
like elements). In FIG. 32A, greater elastic spacing proximate the side edges create
larger capsules Ce. Such end capsules Ce preferably have greater SAP loading and advantageously
present "bumpers" at the side edges effective at preventing side leakage. In FIG.
32B, greater spacing at the center provide for a larger capacity capsule Co. The center
capsule Co is positioned to align with negative curvature regions of the wearer, as
shown in the "baby waist contour" map of FIG. 33. In this instance, the large capsule
CO aligns to accommodate the negative curvature of the back. The elastic core assembly
200 of FIG. 32B may be modified and described as having large capsules Ce that align
to accommodate a negative curvature regions on either side of the baby's tummy.
[0104] Bonding of the elastic filaments to the nonwoven may also be accomplished by adhesives
that can be applied either to a nonwoven facing sheet or to the elastic filament prior
to its inclusion into the composite, or via ultrasonics to entrap the filament in
discrete points or areas on the nonwoven facings. When the adhesive is applied to
the nonwoven facing sheet, it may be applied in an overall manner, as adhesive stripes
or any other discrete pattern. When the adhesive is added to the elastic filaments,
it may be applied over the length of each filament or on selected areas of each filament.
In the instance where the adhesive is applied to the length of each filament, one
option is to bond the elastic filament along its length to only one facing.
[0105] The two facings may consist of nonwovens with basis weights ranging from 8 - 120
grams/square meter (gsm) and of sheet density from 0.03 - 1.0 g/cc. Preferably, the
facing sheet accepting the absorbent particles will be a bulky nonwoven for the purpose
of fixing or immobilizing the particles. At least one of the facings will be hydrophilic,
such hydrophilicity can be conferred by the inclusion of inherently wettable fibers
such as rayon, synthetic fibers treated for wettability, or having the formed sheet
treated for wettability such as surfactant addition, corona or plasma treatment. The
use of a wettable substrate will allow enhanced liquid distribution due to wicking
within the substrate that is supported by a favorable fiber wettability and an appropriate
web density that can support capillary wicking. The web density and wettability combination
can be determined using capillarity considerations (see for example, "Interfacial
Forces in Aqueous Media, 2
nd ed, Carel J. van Oss, p. 140). (A substrate that can support a capillary rise of
at least 1 cm is preferred).
[0106] The loading (amount) of absorbent material (primarily SAP) may be varied from tube
to tube or capsule to/capsule. Additionally, the type of absorbent material or composition
can be varied such as SAP retention capacity, absorption speed, average particle size,
gel strength or permeability. These parameters change the absorption behavior of the
absorbent aggregate such as speed of fluid lock-up, fluid flow rate and movement within
the absorbent composite. Differences in these properties may be used to design specific
flow patterns needed to enhance absorbent article performance. Other absorbent properties
may also be varied through additives such as surfactants for wettability, odor control
agents and the like.
[0107] FIGS. 34A-34B illustrate design and functional variations achieved through modification
of the SAP-free lanes L0 between capsules C and between bond edges to teh elastics.
In FIG. 34A, a narrow SAP-free lane is produced and a single bonding line is directed
along the narrow lane to bond the substrates and elastics. In FIG. 34B, a wide SAP-Free
lane is produced and two bonding lines are used to seal the gap between capsules.
See also FIG. 21C and accompanying description. The width of the SAP-free lane is
varied to produce SAP-free exterior channels of different widths. These channels may
be utilized for enhanced fluid flow along the length of the channels. Alternatively,
more absorbent particles/SAP may be deposited in these exterior channels to provide
additional capacity. (See e.g., FIGS. 35 and36). The, another nonwoven sheet may be
added to cover the additional SAP stripes. This sheet can also provide ADL or topsheet
functionalities. (See FIG. 35). A SAP constituent with properties different from the
SAP within the capsules is preferred for the additional SAP stripe. For example, SAP
with higher permeabilities and slower liquid absorption rates (vortex time) will have
relatively faster liquid spreading, transport liquid to the SAP within the capsules
in a controlled manner and enhance the overall performance of the composite.
[0108] The elastic absorbent composite may also be made as a finished absorbent insert for
use as a removal absorbent core insert. The bottom nonwoven will be hydrophobic and
can function as a breathable backsheet. The upper nonwoven facing can be a multifunctional
material that can function both as an ADL and topsheet. Such a material may be made
from dual layer nonwoven with a density gradient wherein one side is denser than the
other. The denser side will function as the topsheet and the more open side will have
ADL functionality (see FIG. 36).
[0109] FIGS. 34C and 34D illustrate yet further embodiments of the elastic core assembly
200, with like reference numerals used indicate like reference numerals. In FIG. 34C,
a narrow SAP-free lane is produced and a bonding line is applied to seal the lane.
Then, at least in this embodiment, MD -elastics are conveniently applied over the
same narrow SAP-free lane and over the bonding line, thereby creating a multi-directionally
elasticized core assembly 200. The embodiment of FIG. 34D is a variation of the multi-directionally
elasticized core assembly, wherein a wide SAP-free lane is utilized.
Other Design Variations
[0110] The simplified illustrations of FIG. 37 are used to illustrate additional design
variations and applications, and to accompany the brief descriptions below, according
to the present disclosure. The illustrations are of elasticized core assemblies, wherein
like reference numerals are used to indicate like elements.
[0111] FIG. 37A illustrates an elasticized core assembly 200 having a pronounced tubular
shape. The configuration shown may be regarded as one of the basic designs of the
elastic core assembly and applicable for many disposable absorbent applications. These
applications include incorporation into a disposable absorbent diaper having an elasticized
chassis, such as diaper 201 in FIGS. 2, 2A-2C.
[0112] Referring to FIG. 37B, in an alternative embodiment, no folding or corrugating of
the first nonwoven sheet is performed. Instead, the absorbent particles are deposited
in stripes using vacuum assisted or striped material delivery. Examples of striped
material delivery include the use of delivery tubes for depositing particles in stripes.
Baffles could also be placed in the forming path of particle delivery to the substrate
such that the particles are deposited in stripes.
[0113] FIG. 37C illustrates an elasticized core assembly having a plurality of wide, SAP-free
lane. The core assembly may be produced by using a wide elastic filament matrix.
[0114] FIG. 37D illustrates an embodiment of the elastic core assembly, wherein the elastic
construction includes elastic filaments introduced in the MD direction. Furthermore,
at least one filament is disposed along the SAP-free lanes. Preferred bonding may
employed as described above to produce an absorbent composite sandwich that is both
MD and CD stretchable. FIG. 38 further illustrates a method of producing an multi-directional
elastic core assembly 300, wherein like reference numerals are used to indicate like
elements. In Step 1 according to FIG. 38, an elastic filament matrix O2 is produced
from two cross-directional elastic composites O1 that are overlaid. One composite
O1 is configured with the elastic filaments forming an angle between 0 and 90 degrees
relative to the CD-axis and in the plane of the sheet (as in the process described
above). The other composite O1 is preferably configured with the angle direction opposite
that of the first. The angle shift can be produced by relative movement of one edge
of the elastic composite with the opposing edge. The resulting elastic filament matrix
O2 features crossed elastics with an oblique angle between filaments. See FIG. 38.
The resulting elastic absorbent composite is both MD and CD stretchable.
[0115] As further shown in Step 2 of FIG. 38, adhesive may be applied to all elastic filament
surfaces or in discrete area. Alternatively, adhesive may be applied on the substrate
wholly or according to a pattern. The elastic matrix O2 the engages and bonds to the
substrate. Then, SAP is applied in the cells outlined by the elastic matrix, before
a top substrate or facing is applied over the SAP-filled matrix, as shown in Step
3 of FIG. 38.
[0116] It is also contemplated to create non-uniform elastication patterns along the longitudinal
direction by various means such as:
- 1. Periodic variation in the elastic tension of the CD filaments by changing elongation
prior to bonding the composite to the facings. For example, the filaments can be quickly
extended
- 2. Initially uniform tension in the CD filaments followed by deactivation (ie. cutting)
of selected filaments
- 3. Initially uniform tensions, but bonding to attach the elastic filaments to the
facings is non-uniform
[0117] An absorbent core with non-uniform shapes and profiled basis weights can be formed
from a uniformly rectangular composite. For instance, an hourglass-shaped core with
a higher basis weight and higher protrusion in the crotch area/target zone can be
made. Similarly, the array of MD elastic filaments may also be introduced into the
composite at different tensions and can cause the article to conform to preferred
3D configurations. For example, higher tensions along the side edges will result in
a cup-shaped configuration which is advantageous for product fit. The interaction
between non-uniform MD and CD elastication may also produce a variety of configurations
that can result in fit and performance product advantages.
[0118] FIG. 39 illustrates an exemplary system and process for making the absorbent core
assembly 300 described above and in respect to FIG. 38 (wherein, in respect to FIGS.
24 and 38, like reference numerals are used to indicate like elements). The system
in FIG. 39 may also be described as a modification of the system earlier described
in respect to FIG. 24B.
[0119] Although the presently disclosed product, system and\or process and their advantages
have been described in detail, it should be understood that various changes, substitutions
and alterations can be made herein without departing from the scope of the disclosure
and as defined by the appended claims. Moreover, the scope of the present disclosure
is not intended to be limited to the particular embodiments of the process, machine,
manufacture, composition of matter, means, methods and steps described in the specification.
As one of ordinary skill in the art will readily appreciate from the disclosure, processes,
machines, manufacture, compositions of matter, means, methods, or steps, presently
existing or later to be developed that perform substantially the same function or
achieve substantially the same result as the corresponding embodiments described herein
may be utilized according to the present invention. Accordingly, the appended claims
are intended to include within their scope such processes, machines, manufacture,
compositions of matter, means, methods, or steps.